The present invention relates to methods and apparatus for precisely dispensing fragrances and other volatile materials, synthesizing custom fragrances in real time and calibration of electronic sensors.
Odoriferous substances can be dispensed by numerous methods including passive wicks, aerosol xe2x80x9cpuffersxe2x80x9d, fine particle sprayers and scented candles. Control of the initiation and cessation of sensory experience resulting from conventional dispensing is very difficult. Except in a gross sense, the quantity of odor producing material dispensed is not controlled. It is particularly difficult to cease producing an aroma sensation once begun and miniaturization is not readily achieved. Passive dispensing devices such as wicks or candles require material that remain relatively stable in air as a vapor and are able to withstand heat, for example. Materials which are readily oxidized at room temperature, photodecompose or hydrolyze in humid air are all examples of evanescent fragrances for which periodic active dispensing is the only practical way to produce the fragrance.
The most common method of dispensing fragrances or aromas is the wick method in which a wick in contact with a volatile liquid is exposed in a space. It is evident that once the wick is exposed, there is no way to control the amount of material dispensed nor to easily adjust it or quantify it. It can""t conveniently be turned on and off. None of the conventional devices for distributing odor producing chemicals are subject to digital control or quantitative precision dispensing.
The prior art uses the same dispensing methods for the purpose of odor masking or eliminating vapors. Three approaches to removal of bad orders can be considered: A) perceptual masking, B) specific or nonspecific olfactory receptor blockade and C) odor molecule binding or metabolism. It would be desirable to have a precise active jet dispensing method for all three of these approaches because it allows the best odor removal materials to be dispensed interactively, in response to the presence of any specific bad odor. All of these strategies are in part used by companies such as EnviroCon, AMAX, Elim-N-Odor, Inc., BioZapp Labs, inc., Technaal, Inc., and OdorGone (Ray Market).
Perceptual masking is an approach whereby a competing smell is introduced in a sufficient intensity to xe2x80x9cmaskxe2x80x9d the offending odor whereby the subject is aware of both odors but with reduced attention paid to the offending odor. Olfactory receptor blockade can be an effective odor removal strategy if the offensive order is detected by a single receptor type in the nose whereby pharmacologic blockade of that specific receptor with a receptor blocking ligand, will produce a specific xe2x80x9csmell blindnessxe2x80x9d for that smell. This is superior to the use of vapors of formaldehyde or cocaine or zinc oxide cream which have been used as non-specific receptor blocking agents which cause complete anosmia or hyposmia. Odor molecule removal by catabolysis of the molecule or binding another macromolecule to it can both remove the materials from the air and thus remove the odor. There are commercially available products intended to remove specific odors by one of these methods. All of these approaches could benefit from a device or method that would provide dispensing accuracy and precise control.
There is a significant need for accurate controlled dispensing of pharmaceuticals, herbs and psychoactive substances of all types. Potent psycho-active materials like cocaine, adrenalin, and amphetamine can be electronically dispensed from physician""s direction using devices such as inhalers. Specific chemicals to control asthma are examples of such use. A more precise method of dispensing would be expected to produce an improvement in controlled dosage. Emergency personnel and military are obviously targets for emergency psycho-stimulant use. Nonprescription drugs like caffeine, nicotine, theopholine, ginseng, and others could also be dispensed in inhalable formulations for use in a variety of medical or even non-medical applications. Pheromones or other natural or synthetic materials that alter behavior and physiology via a nasal inhalation route are also subjects for precise controlled dispensing. Odoriferous materials that affect mood, arousal, stress or other dimensions of human behavior and physiology through primarily olfactory perceptual routes can benefit from improved dispensing apparatus. The invention of this application is a superior method for dispensing such compounds because dispensing can be precise, metered, interactive, and the dispenser can be tamperproof with prescribed dispensing rates possible. It would be desirable to have a dispensing device that was both discreet, digital and programmable, and in many foreseeable applications desirable to provide miniature devices which take up less space and are economical to manufacture and produce. The present invention makes these possible.
The present invention is directed to ink-jet based systems for the micro-dispensation and vaporization of volatile materials obtained from odor producing fluids or materials which can be melted or dissolved in fluids. The invention relies upon tiny electronically operated fluid droplet ejection devices having a fluid supply reservoir and a droplet ejection orifice aimed to deposit fluid droplets onto a target medium or space. The fluid supply reservoir is provided with a viscosity adjusted odor sensation producing fluid which is ejected in a stream of sequential droplets in response to electrical signals comprising voltage pulses. The preferred fluid droplet ejection device comprises one or more piezoelectric actuators but ejection devices can be made with other types of actuators such as magnetoresistive, inductive, thermal or miniature pressure solenoid valve. Pulses are provided by drive electronics operably connected to the ejection device or a plurality of such ejection devices and a system controller operably connected to the drive electronics and a power source whereby operating signals are delivered to the drive electronics to cause sequential droplets of fluid to be deposited onto the target medium or space. A typical orifice size is approximately 60 micrometers. Droplets in the range of 10 micrometers to over 350 micrometers are possible by varying known parameters of ink-jet printing heads.
In one embodiment the fluid droplet ejection device or devices are enclosed in a housing containing a target medium and air-flow outlet. In a variation of the invention, the target medium is a heater having a heated surface operated by the system controller and positioned to intercept ejected droplets deposited thereon. Air moved by an air movement device may be used to increase volatilization of fluid deposited on the target medium by the ejection device. The heater has little or no heat sink characteristics because of its low mass and small size. The heater has a quickly heatable surface upon which fluid droplets are deposited which equally quickly falls back to ambient temperature when not powered.
In a further variation, the heater is a plurality of heaters individually controlled to quickly raise the temperature of the heatable surfaces to vaporized fluid droplets deposited thereon when the ejection device is operated and return to an unheated state when ejection ceases in order to control vaporization of deposited fluid. In some applications the heater temperature is preset, based upon the fluid being ejected, and held constant at the specified temperature. Air movement means may be used to force air over the heated surface or surfaces and thereby carry vapor from a passageway through the air-flow outlet. Individual fluid droplet ejection devices including the reservoir have been produced having a length less than one centimeter and a diameter less than two millimeters. Such miniaturization makes new applications and methods possible in connection with dispensing fragrance, aroma and odor producing materials.
The present invention has utility in applications such as a virtually reality display system for entertainment or training, instrumentation including medical instrumentation, conditioning of environments, odor masking systems, fragrance synthesis, medication delivery, computer output systems (fragrance display), communication systems and calibration inputs for electronic chemical sensor systems.
In another embodiment of the invention, a printhead having a plurality of electronically operated fluid droplet ejection channels each having a fluid supply reservoir containing volatile fluids which produce different aromas or fragrance components. The channels are selectively operated by a system controller to deposit fluid on a target medium where they can volatilize to produce a custom aroma or fragrance. In combination with a programmed computer which selectively operates the fluid droplet ejection channels in different combinations or at different rates or upon differentially heated surfaces, a unique and reproducible fragrance or aroma can be produced and reproduced. By altering the selection of fragrance components or the relative amounts thereof, an original odor effect can be quickly and precisely changed to produce a second or a third or more different odor effect merely by changing the voltage pulse signals which operate selected channels.
The microdispensing ink-jet based systems of the present invention allow the study of numerous properties of the sense of smell, including studies of temporal integration times, inter-nostril summation, backwards and forwards masking, and other phenomena that have only received cursory attention due to methodological limitations based on existing systems. The microdispensing ink-jet based systems of the present invention provide precise control of both the temporal envelope of the stimulus and the total number of molecules constituting the stimulus. Although conventional olfactory testing machines are available, only large well-funded organizations can afford them because of high costs.
The present invention provides a means for conducting such research at a fraction of the cost of conventional olfactory research testing equipment. In addition, it overcomes disadvantages and drawbacks of existing olfactory test and sensory stimulation formats because it is fully automatic, more convenient, faster and more precise. Because ink-jet dispensing of airborne materials is precise, discrete, digital, programmable and interactive, the speed and accuracy of dispensing materials to become airborne is several orders of magnitude better than can be obtained by any other method. Moreover, because devices can be made small, the size of the systems can be reduced to a few cubic inches. Since the present invention is controlled by digital electronics, all types of digital computer and interactive control is possible. Many different rates, intensities and combination of airborne materials can be presented at a mere keystroke or switch closure. Because the systems of the present invention can dispense volumes as small as a few tens of picoliters of fluid, they can provide exquisitely fast and precise olfactory inputs near the threshold (approximately 10 billion molecules) of human olfactory.
The miniature size of the devices of the present invention make novel applications possible. The devices can be fitted inside any air handling systems (such as scuba airways, pilot airways, automotive air handlers, etc.), and can be worn (on glasses, helmets, decorative pins, microphone holders, etc.) or can be concealed near objects (in headrests, door jambs, table centerpieces, television chassis, etc.). All of these applications open exciting new horizons to olfactory access not heretofore available. Other patent applications in related art by inventors with an obligation to assign to the owner of the present application are U.S. application Ser. No. 08/837,646, filed Apr. 21, 1997 entitled xe2x80x9cPresenting Airborne Materials to the Nosexe2x80x9d, and U.S. Ser. No. 09/110,486, filed Jul. 6, 1998, entitled xe2x80x9cMethod and Apparatus for Dispensing Airborne Materials for Controlling Pests, incorporated by reference herein.
An interesting commercial application of the present invention lies in the entertainment field in the installation of a plurality of ink-jet dispensing systems throughout a movie theater and programmed to quickly produce odors synchronized with the film being shown. They can be quickly turned on or turned off under programmed control to enhance the theater going experience.
Finally, the precise control offered by the ink-jet based dispensing system of the present invention can be used as a real time calibration source for electronic sensors which, although in their infancy are the subject of considerable developmental activity as a means for detecting and measuring odors. Calibration of these devices is particularly significant because they are known to drift in response to ambient conditions such as temperature and relative humidity. The reproducible delivery of a known quantity of a known material makes real time baseline calibration possible. In the converse of this, electronic sensors can be used to verify the operation of the ink-jet dispenser where it is important to make sure the dispenser is functioning.